Ephesians 2:4-9:
But God, being rich in mercy, because of His great love with which He loved us, even when we were dead in our transgressions, made us alive together with Christ (by grace you have been saved), and raised us up with Him, and seated us with Him in the heavenly places, in Christ Jesus, in order that in the ages to come He might show the surpassing riches of His grace in kindness toward us in Christ Jesus. For by grace you have been saved through faith; and that not of yourselves, it is the gift of God; not as a result of works, that no one should boast.
Hebrews 9:26-27 :
Then Christ would have had to suffer many times since the creation of the world. But now he has appeared once for all at the end of the ages to do away with sin by the sacrifice of himself. 27Just as man is destined to die once, and after that to face judgment,
Hebrews 10 9:14
9Then he said, “Here I am, I have come to do your will.†He sets aside the first to establish the second. 10And by that will, we have been made holy through the sacrifice of the body of Jesus Christ once for all. 11Day after day every priest stands and performs his religious duties; again and again he offers the same sacrifices, which can never take away sins. 12But when this priest had offered for all time one sacrifice for sins, he sat down at the right hand of God. 13Since that time he waits for his enemies to be made his footstool, 14because by one sacrifice he has made perfect forever those who are being made holy.
Romans 3 23:24
for all have sinned and fall short of the glory of God, and are justified freely by his grace through the redemption that came by Christ Jesus.
Ephesians 1 13:14
13In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise, 14Which is the earnest of our inheritance until the redemption of the purchased possession, unto the praise of his glory.
Romans 8 31:39
31What, then, shall we say in response to this? If God is for us, who can be against us? 32He who did not spare his own Son, but gave him up for us all–how will he not also, along with him, graciously give us all things? 33Who will bring any charge against those whom God has chosen? It is God who justifies. 34Who is he that condemns? Christ Jesus, who died - more than that, who was raised to life - is at the right hand of God and is also interceding for us. 35Who shall separate us from the love of Christ? Shall trouble or hardship or persecution or famine or nakedness or danger or sword? 36As it is written: “For your sake we face death all day long;
we are considered as sheep to be slaughtered.â€Â[l] 37No, in all these things we are more than conquerors through him who loved us. 38For I am convinced that neither death nor life, neither angels nor demons,[m] neither the present nor the future, nor any powers, 39neither height nor depth, nor anything else in all creation, will be able to separate us from the love of God that is in Christ Jesus our Lord.
To name a few...To say we can lose our salvation is to say that the Blood wasn't good enough. We have all sinned and fallen short. If works do not save us, how can works keep us saved? Once and for all...